1. Field of the Invention
The present invention relates generally to centralizer devices used in rock and soil anchoring applications. More particularly, the present invention relates to a novel centralizer device with an in-place component tool used to make optimized adjustments to the diameter size of the centralizer device for each of numerous applications
2. Description of the Related Art
Centralizers are devices used to provide space between an anchorage and the walls of an anchor bore hole, thereby allowing grout to be injected into the bore hole for securing of the anchorage. The centralizer field includes many different inventions which have attempted to prove the functions of the centralizer. Its two primary functions are to: 1) provide space between the anchorage and the walls of the bore hole, and 2) to provide a locking mechanism for the several centralizer elements so that they do not fail once installed in the ground.
More specifically, Known relevant prior art has focused on improving the locking mechanism. Unfortunately, patented inventions in this field still exhibit many problems and disadvantages which the present invention has overcome. Even though previous designs have had some success in overcoming past problems, remaining problems include inflexibility in meeting multiple applications, relatively complex locking mechanisms, and using heavy materials such as steel. In addition, known prior art virtually neglects the problem of optimizing the space between the anchorage and the bore hole walls for each application. As is well known in the art, grout is used to secure the anchorage in a bore hole. The more secure the anchorage, the safer the entire anchorage, thereby minimizing the possibility of a failure of a dam, a transmission tower, or an oil well, or other anchor applications.
Therefore, it is clear that a need exists for an improved centralizer system that optimizes the spacing around the anchorage, provides a simple yet effective locking mechanism, allows use in multiple applications, is light weight, strong, and is even more cost effective than existing centralizers. The present invention overcomes these and many long-standing and even ignored problems and disadvantages of the prior art.
Some of the related prior art includes the following U.S. patents: Wills, et al. U.S. Pat. No. 4,042,022; Ferstay U.S. Pat. No. 4,866,903; Chickini, Jr. et al. U.S. Pat. No. 4,247,225; Dane U.S. Pat. No. 4,077,470; Wilson U.S. Pat. No. 4,269,269; Spikes U.S. Pat. No. 4,651,823; Patterson et al. U.S. Pat. No. 4,909,322; Svenson U.S. Pat. No. 4,520,869; and Kraft U.S. Pat. No. 4,143,713.
Wills, et al. discloses a centralizer device with a plurality of blades received in slots by a pair of cylindrical collars. This invention is directed towards preventing the separation of parts during use. Disadvantages to this design include the lack of flexibility in the blade material, a design directed to a specific dimension envelope for the centralizer, and an assembly requiring hammers to insert the steel blades, and therefore requiring a lengthy assembly time.
Ferstay discloses a one piece centering device for thread bars. The device has holes to allow grout to pass around or through the device. Disadvantages to this device include restricted applications because of its small size, and lack of an expanding feature to fit different size bore holes. The device seems directed to use only in building applications. Another disadvantages is the small size of the holes in the device to allow grout to pass. It appears that it would be difficult for grout to pass through the small holes in sufficient quantities to provide sufficient force transfer to the ground for a safe anchor. Still another disadvantage is the use with threaded bar. Installing the device takes more time than would an non-threaded device.
Chickini, Jr. et al. discloses an alignment device comprising a single component for mounting an anchor cable in an elongated cable hole in a guy line anchoring environment. One disadvantages with the device is the fixed diameter of the collar for passing cable through. Another disadvantage is the small diameter of the collar for passing any cable through. Still another disadvantage is the somewhat complex locking mechanism to prevent the device from coming apart.
Dane discloses a well centralizer directed to an improved means to connect bow elements to collars. Disadvantages to this device include a complex connecting apparatus, limited applicability in that it is for use only in oil well casings, use of relatively heavy steel for material, and also a need to bend the locking tab to allow for locking the bow elements into the collars.
Wilson discloses a deformable tab on collars as a means to prevent each spring from disengaging from the end collars when the centralizer is subjected to compressional loading. One disadvantage to this device includes limited applicability in that use is only directed to oil, gas, or water drilling situations. Another disadvantage is that the deformable tab does not appear to be of a robust design, therefore the tab is likely to break. Still another disadvantage is that numerous conventional tools, including hammers, vises and pipe wrenches are need for assembly. Yet another advantage is the metal material used requiring forging. The metal material, being relatively heavy compared to plastic, requires more costs for manufacture, crating and shipping. Spikes discloses a well bore centralizer directed to an improved connectible means between the bowed elements and the collars. Disadvantages include a complex collar locking design, bow elements set to a specific arcuate position, and the hammer force required for assembly. Still another disadvantage is the use of metal in the design, thereby requiring more costs for manufacturing, crating and shipping.
Patterson et al. disclose a casing centralizer with bendable tab to allow a more improved locking mechanism to secure the bow springs in the collars. Disadvantages to this device are similar to others listed in previously mentioned prior art. One advantage is the inability of the device to be flexible thereby limiting its applicability to only certain sizes of bore holes. Another disadvantage is the use of metal which increases costs for manufacture, crating and shipping. Yet another disadvantage mentioned in some of the other prior art is the need to bend the metal before the bow springs can be inserted into the collars. Bending the metal can create a point for failure after installation.
Svenson discloses a centralizer for a well casing directed specifically to a third channel of the collar compressible at final assembly allowing for locking of the bow and collar together. Disadvantages in using this device include the complex locking mechanism, limited use to well casings, use of metal requiring more costs, and a need to use hammering tools before assembly can be completed.
Kraft discloses a self-centering basket for use in mining or oil fields. More specifically, the device is directed towards lugs to hold down steel bars to prevent the bars from jumping out of engagement. Disadvantages include the use of steel, thereby increasing manufacturing and shipping costs. Because the design is meant to be locked upon assembly, no means are provided for mistakes in assembly. It would appear to be virtually impossible to disassemble to correct mistakes. In addition, no means are disclosed for altering the outer dimensions of the device should the on site diameter of the bore hole be greater or less than expected.
In summary, all the cited patents have a multitude of disadvantages. As is quickly realized, most of the patents disclose similar attempts to solve one problem with previous centralizer designs. Most are directed to improving locking techniques. However, problems still exist with attempts to improve locking techniques. Therefore, it is an object of the present invention to solve the locking problem with an elegant, simple, inexpensive design. In addition, the present invention solves other problems in the field that have been virtually ignored, Therefore it is an object of the present invention to provide a flexible design allowing adaptability in the field to different diameter bore holes. Also, the unique features of the present invention allow use in virtually any anchoring use. It is a further object of the present invention to use a non-metal material, thereby reducing costs throughout the manufacturing to end use process and eliminating the need for any use of conventional tools for assembly. Another object of invention is to provide numerous embodiments for optimized use in the field, including providing for errors in assembly, in customer specifications, or customer orders.